EC [Epistemic Contextualism], in the sense in which it concerns us here, is a relatively recent development. Nevertheless, in the latter half of the 20th century, several at-times overlapping strands emerged which, in one way or another, made ‘contextual’ factors of central importance to certain epistemological questions, thereby setting the stage for EC in its contemporary form.
http://plato.stanford.edu/entries/contextualism-epistemology...